Coin processing machines generally have the ability to receive bulk coins from a user of the machine. Coin processing machines include a redemption type of machine wherein, after the deposited coins are counted, a receipt is issued indicating the value of the deposited coins. The user may redeem this receipt for the amount of deposited coins in the form of banknotes. In other embodiments, the receipt is redeemed for the amount of the deposited coins less a commission charged for use of the coin redemption machine.
These self-service prior art coin redemption machines are commonly used in a banking environment and a retail environment such as a grocery store. In operation, a user inputs (i.e., deposits) a batch of coins of mixed denominations into a hopper of the coin redemption machine. The machine determines the value of the deposited coins and outputs a receipt indicative of the determined amount. In some embodiments, the receipt also indicates a second, lesser amount, which reflects a commission charged for use of the machine. The user redeems the receipt for paper currency for the value of the deposited coins less the commission. For example, in a banking environment, a user redeems the receipt at the teller's window. In a retail environment, the user can redeem the receipt at a cashier's station or a customer-service station.
A problem associated with coin redemption machines is that they are self-service in nature—a customer of a grocery store, for example, deposits that customer's coins into the machine. The self-service nature of the machine lends itself to foreign objects being deposited with the coins more frequently than in the situation where the machine is operated by an experienced and trained operator. Prior art coin redemption machines have focused on removing foreign objects that are included with the coins by providing perforated surfaces for sifting out the foreign objects and draining liquids from the coins, magnets for attracting ferric foreign objects, and fans for moving air over the coins to blow out light foreign objects. These cleaning measures, however, have focused on removing foreign objects prior to the objects being input into the coin processing mechanism (e.g., a disk-type coin sorter) of the redemption machine and have not addressed the situation where foreign objects have bypassed these cleaning measures and are input to the coin processing mechanism. Examples of foreign objects include rings, watches, nuts, bolts, and washers as well as damaged or bent coins and tokens. Failure to remove these objects can cause damage to both the objects and to the coin processing mechanism. Thus, there exists a need for a coin redemption machine that can detect the presence and provide for the removal of foreign objects input to the coin processing device of the coin redemption machine.